Solvent power is generally characterized by the Kauri-Butanol index which is the volume in ml at 25° C. of a solvent necessary to produce a defined degree of turbidity when 20 g of a standard solution of Kauri resin in n-butanol is added. This index is equal to 57 for 1,1-dichloro-1-fluoroethane (known under the name HCFC-141b).
Apart from its good solvent power, HCFC-141b is also characterized by a low surface tension (equal to 19.3 mN/m) which gives it very good surface wettability. Since the boiling point of HCFC-141b is equal to 32° C., this enables it to evaporate rapidly and in this way to facilitate deposition of dissolved products onto substrates. Finally, HCFC-141b does not have a closed cup flash point and is therefore a non-flammable solvent.
HCFC-141b thus possesses properties that give it a good ability to dissolve many organic compounds, in particular silicone oils.
However, by reason of its action on the ozone layer which is not zero (ozone degradation potential ODP=0.11), HCFC-141b is subject to important regulations that increasingly aim to eliminate it. Thus, the European regulations on substances harmful for the ozone layer (No. 2037/2000) prohibits the use of HCFCs (hydrochlorofluorocarbons) such as HCFC-141b in solvent applications after 1st Jan. 2002, except for the aeronautic and aerospace fields where prohibition takes effect from 2009 in Europe.
Document EP 974642 proposes an azeotropic composition of 1,1,1,3,3-pentafluorobutane (known under the name HFC-365 mfc) and 1,1,1,2,3,4,4,5,5,5-decafluoropentane (known under the name HFC-4310mee) as substitutes for HCFC-141b because they do not have any effect on the ozone layer. However, the Kauri-Butanol index of such a composition is much lower than for HCFC-141b. The Kauri-Butanol index for HFC-365mfc is 12 and is equal to 9 for HFC-4310mee.
Document EP 1 354 985 proposes, by replacing HCFC-141b, a cleaning fluid for refrigeration installations comprising a cleaning oil mixed with a liquefied carrier gas with which it forms a cleaning foam by expansion.
Moreover, a composition is known comprising 30 to 70% by weight of 1,1,1,3,3-pentafluorobutane and 70 to 30% by weight of methylene chloride (FR 2 694 942).
A composition is also known from document WO 00/56833 comprising HFC-4310mee, HFC-365mfc and trans-1,2-dichloroethylene. Examples 4 and 5 of this document describe solubility tests at ambient temperature with mineral oil and silicone oil DC-200.
Moreover, within the field of environmental protection, the current tendency is towards a reduction in solvent emission by evaporation. Thus in many so-called emissive applications, that is to say for which the solvent is capable of evaporating into the air, solvents are sought that are effective at a lower temperature than ambient.